The panic played on the innate fears of many people in their beds at home at night: a prowler in the dark, unseen, with a terrible weapon. They were rendered paralyzed, helpless; unconscious and unaware; unable to call for help. It was Mattoon, Illinois, in the autumn of 1944. A number of residents reported waking in the middle of the night to a strange, sickly odor; experiencing various symptoms, including paralysis; and in some cases, seeing a prowler pumping some kind of gas into their house through an open window. The Mad Gasser of Mattoon was never caught, his victims never clearly diagnosed, his motives never revealed. Indeed, his very existence was never even proven. Some say it was merely mass hysteria, or some other skeptical claim. Today we're going to find out what we actually know about the Mad Gasser, and see what lessons the skeptical mind can learn.

First of all, it is important to note a significant historical context to the Mad Gasser attacks: that the United States was currently at war with Nazi Germany. Poison gas attacks were an entirely realistic worry, perhaps even more realistic than many knew: Only two months after the Mad Gasser panic, the Japanese began sending balloons loaded with incendiary bombs against the US west coast. Of some 9,000 launched, about 10% are estimated to have made it all the way, and a few people were even killed by them. In 1944, it was far more prudent than it was paranoid for Illinois residents to worry about German agents possibly roaming around their town with poison gas. Later we learned that gas was only rarely used by any side in World War II (for a variety of reasons), but it had seen widespread use in World War I and concern was well justified.

Mattoon is a small manufacturing town at the junction of two railroads in the midst of endless plains of midwestern agriculture. Its encounter with the Mad Gasser began on the night of September 1, 1944, just as Allied troops in Europe were recapturing France and Belgium and Germany began to scramble for an advantage. But here, half a world and an ocean away, residents thought themselves safe. A young mother, Aline Kearney, awoke late at night from a strange sweet odor, and when one of her daughters who was in bed with her also woke up with the same complaint, she discovered her legs paralyzed. She called for her visiting sister who came in, and smelled the odor apparently coming from the open window. They called the police, who found nothing, but noted that Mrs. Kearney had recovered from her paralysis. But two hours later, her husband came home from his work driving a cab, and spotted a prowler outside the house. The police were called again, but again, found nothing.

Mattoon's only newspaper, the Daily Journal-Gazette, ran the following headline across its front page:

ANESTHETIC PROWLER ON LOOSE Mrs. Kearney and Daughter First Victims Both Recover; Robber Fails to Get Into Home

Even for a newspaper, that's a lot of assumptions: first, that these were only the "first" victims; second, that the prowler was using some sort of anesthetic; and third, that he was a robber. But it was enough. Within days, several more people called police saying that they too had been attacked by the prowler they read about in the newspaper. Their stories were published in the paper on September 5, owing to no publications on Sunday and the Labor Day holiday.

And that's when the real melee began. Two more people, upon reading those new stories, reported Mad Gasser attacks to the police. Several more were reported almost every day. The headline read:

MAD ANESTHETIST STRIKES AGAIN

September 10 saw the highest number of reports to police at seven. Each day, the newspapers (by now the story had spread to other papers) devoted more and more space to it. By the 11th, the Chicago Herald-American plastered its front page with 1.5-inch type:

STATE HUNTS GAS MADMAN

Over 13 days, a total of 25 attacks were reported. Sometimes a prowler was spotted; once he was reported as appearing to pump the handle of a Flit gun (a handheld spraying device like a bicycle pump with a cylinder of some chemical attached). Always the sweet odor of gas was described, though the symptoms it produced were all over the map. Some reported a burning of the mouth, throat, or lips; some reported nausea; and only a few mentioned the temporary leg paralysis. By the time police arrived, all the symptoms for all the victims had cleared up, and nobody suffered any lasting effects. Neither was any evidence ever found of either a prowler or any kind of gas, except once: One woman reported following the smell to a cloth folded on her front porch, which she picked up and smelled, causing immediate painful irritation to her mouth and throat. When police tested the cloth, they found nothing.

At the height of this small town's small frenzy, bands of citizen vigilantes began patrolling the streets, looking for the prowler. Police warned them that vigilantes could be arrested as well, but as it might have escalated, it stopped. Just as the tiny borders of Mattoon seemed strained with Mad Gassers outside every house, the character of the newspaper reports changed dramatically. The headlines became:

THE MANHUNT FOR MR. NOBODY

They changed from reports of a Mad Gasser to interviews with social psychologists discussing the phenomenon of mass hysteria. And as soon as that became the tone, suddenly there were zero more police reports.

And so, within two weeks of its birth, the Mad Gasser of Mattoon became one of the most famous case studies in mass hysteria. The following year, Donald Johnson, an undergrad at the University of Illinois, wrote the only really scholarly article about the episode, "The Phantom Anesthetist of Mattoon: A Field Study of Mass Hysteria" published in the Journal of Abnormal and Social Psychology. His most interesting findings were his graphs of newspaper space in square inches compared to the number of reports that came in, showing a very apparent causal effect. If the morning newspapers dedicated more space to it, more reports would come in that day. And, interestingly, the Mad Gasser was as silent as the newspapers during that initial 2-day Labor Day publishing break. Of course, 25 reports over 13 days is a very small data set, so it's not really valid to call such conclusions definite. But given the lack of evidence to the contrary, most subsequent researchers have agreed that the initial analysis of mass hysteria driven by newspaper reporting was probably the only real cause behind the Mad Gasser.

Adding to the unlikeliness of a more corporeal perpetrator were the reported physiological effects of the alleged gas. There simply aren't any known gases that cause temporary paralysis of the legs, plus all the other effects, yet leave the victim symptom free within the space of only a few minutes. But many writers, especially paranormal writers, have tried hard to make the Mad Gasser into a real attacker.

Both chloroform and ether have often suggested as potential gases that the alleged attacker might have used with his spray gun. Both are popularly associated with anesthesia, and both are said to have a slightly sweet odor or taste. If you took a spray gun and pumped it into the window of a house, could you induce the type of effects reported?

These were pretty small houses, and a quick calculation suggests that they enclosed perhaps 250,000 liters of air. Chloroform begins to take effect at 100 parts per million, thus requiring 25 liters of chloroform gas. Certainly a Flit gun could not do this. Neither chloroform nor ether produce paralysis in the legs as the victims are said to have reported. They can both produce a more dangerous type of paralysis, though, if overdosed: respiratory paralysis, which leads to death, and is not consistent with the Mattoon reports. From a medical perspective, we can dismiss both chloroform and ether.

One author, high school chemistry teacher Scott Maruna, believes the attacks were the work of an actual flesh and blood Mad Gasser, as detailed in his 2003 book The Mad Gasser of Mattoon: Dispelling the Hysteria. Maruna pointed to a town loner — antisocial, homosexual, alcoholic, and living in a trailer in his parents' yard — Farley Llewellyn, and nitromethane, perhaps most familiar as Top Fuel drag racing fuel. Though he doesn't supply the proof, Maruna states that all of the victims on the first weekend had been high school classmates of Farley's, and that his family committed him to an asylum on September 11, when the attacks stopped. Most interestingly, Maruna cited personal correspondence with a Mrs. Upton, the Llewellyns' next door neighbor, who recalled that about a week before the attacks, a small explosion rocked Farley's trailer. She said he kept a not-very-secret laboratory in there. A small explosion would certainly be consistent with nitromethane, and its high volatility would also explain why police were able to find no remaining trace of any chemical on the cloth one victim found on her porch, or any remaining odor at any victims' residences.

Chemical addicts with backyard laboratories suggest compounds other than nitromethane to me, and if Maruna's tales of the apocryphal Farley Llewellyn are true, it's not much of a stretch to suggest that he may have been experimenting with methamphetamine. And, coincidentally, that's a drug the Nazis were supplying to many of their soldiers as a stimulant; and so, the feared Nazi connection to Mattoon may have had some substance to it after all. As a liquid, perhaps in the cylinder of a Flit gun, it is said to smell like geraniums. Might an antisocial addict be more inclined to spray a psychoactive drug through the windows of those who had shunned him, than a substance like nitromethane with no special expected effects? Who can guess.

A cursory search of public records in Mattoon did turn up Llewellyns in the 1940s, but none matched any of the first names given by Maruna. I didn't really pursue it, because it doesn't really matter. We have only a third-hand anecdote that even suspected Farley may have been involved, and certainly no evidence. But Maruna's basic explanation is compelling. A real person may indeed have caused the first few attacks with some sprayed substance, which triggered newspaper reports, which triggered paranoia and hysteria whenever anyone smelled natural gas or anything else over the course of those two panicked weeks. Whether or not Farley Llewellyn (or anyone else) did prowl the dark streets of Mattoon with a Flit gun (or something) filled with liquid meth (or anything else) is a question that will remain unsolved, but for the subsequent newspaper-driven frenzy, mass hysteria is indeed a textbook-perfect explanation.